St. Cyprian of Carthage ~ The Church is one...He who does not hold this unity does not hold the Law of God.
This past Sunday as I was praying silently the Canon with the priest, the words of the Communicantes hit me. First and foremost, we are to be Communion with the Blessed Virgin and all for the martyr saints mentioned in that prayer. So the unity starts with unity in the faith held by those Saints, not with anyone who contradicts the true faith. Therefore the "una cum" referenced in the Te Igitur can only refer to those who hold the same faith as those saints. Ask yourself, do those who currently run the Church hold the same faith as the saints mentioned in the Canon?
P N F This is super difficult problem. on one hand: "St. Catherine of Siena ~~~ Speak the truth in a million voices. It is silence that kills..."
And also Saint Catherine from her Letters (specifically Letter T207, written to Cardinal Pedro de Luna, later Antipope Benedict XIII):
"Even if the Pope were the incarnate demon, we ought not to lift up our heads against him, but to be always calm and obedient to his will, for the sake of God, who commands us to obey him."
(Italian: "Anche se il Papa fosse Satana incarnato, non dobbiamo alzarci contro di lui... ottemperare e obedire alla sua volontà.")
Who knows what to do?
Yes, but St. Catherine's counsel assumes that the person who claims to be the Pope is actually the Pope. She certainly did not shy away from lifting up her head and speaking against people who she knew to be antipopes.